So I need to know how to provide spacing between my textfield and button on the screen – Flutter

So Basically the issue i am facing is I need to provide equal amount of spacing from the left side and the right side of the screen

The code of my file is attached below the code is in flutter

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter/src/widgets/container.dart';
import 'package:flutter/src/widgets/framework.dart';

class PhoneNumberDetails extends StatefulWidget {
  const PhoneNumberDetails({super.key});

  @override
  State<PhoneNumberDetails> createState() => _PhoneNumberDetailsState();
}

class _PhoneNumberDetailsState extends State<PhoneNumberDetails> {
  TextEditingController countryCode = TextEditingController();
  @override
  void initState() {
    // TODO: implement initState
    countryCode.text = '+91';
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(
          'Verify Number',
          style: TextStyle(color: Colors.white, fontSize: 20),
        ),
      ),
      body: Container(
        alignment: Alignment.center,
        child: SingleChildScrollView(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              Image.asset(
                'assets/otpimage.png',
                height: 150,
                width: 150,
              ),
              Text(
                'Phone Verification',
                textAlign: TextAlign.center,
                style: TextStyle(fontSize: 20, fontWeight: FontWeight.bold),
              ),
              SizedBox(
                height: 10,
              ),
              Text('Please enter your mobile number to get started'),
              SizedBox(
                height: 25,
              ),
              Container(
                height: 55,
                decoration: BoxDecoration(
                  border: Border.all(width: 1, color: Colors.grey),
                  borderRadius: BorderRadius.circular(5),
                ),
                child: Row(
                  mainAxisAlignment: MainAxisAlignment.center,
                  children: [
                    SizedBox(
                      width: 10,
                    ),
                    SizedBox(
                      width: 40,
                      child: TextField(
                        controller: countryCode,
                        keyboardType: TextInputType.number,
                        decoration: InputDecoration(
                          border: InputBorder.none,
                        ),
                      ),
                    ),
                    Text(
                      "|",
                      style: TextStyle(fontSize: 33, color: Colors.grey),
                    ),
                    SizedBox(
                      width: 10,
                    ),
                    Expanded(
                      child: TextField(
                        keyboardType: TextInputType.phone,
                        decoration: InputDecoration(
                          border: InputBorder.none,
                          hintText: "Phone",
                        ),
                      ),
                    ),
                  ],
                ),
              ),
              SizedBox(
                height: 20,
              ),
              SizedBox(
                width: double.infinity,
                height: 45,
                child: ElevatedButton(
                  style: ElevatedButton.styleFrom(
                    backgroundColor: Colors.green.shade600,
                    shape: RoundedRectangleBorder(
                      borderRadius: BorderRadius.circular(10),
                    ),
                  ),
                  child: Text('Send Code'),
                  onPressed: () {
                    Navigator.pushNamed(context, 'verify');
                  },
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }
}

Basically i need the output in the following way

The output of this code is: